title: Copy number variations (CNVs) identified in Korean individuals.
abstract: BACKGROUND
  Copy number variations (CNVs) are deletions, insertions, duplications, and more complex variations ranging from 1 kb to sub-microscopic sizes. Recent advances in array technologies have enabled researchers to identify a number of CNVs from normal individuals. However, the identification of new CNVs has not yet reached saturation, and more CNVs from diverse populations remain to be discovered.
  
  
  RESULTS
  We identified 65 copy number variation regions (CNVRs) in 116 normal Korean individuals by analyzing Affymetrix 250 K Nsp whole-genome SNP data. Ten of these CNVRs were novel and not present in the Database of Genomic Variants (DGV). To increase the specificity of CNV detection, three algorithms, CNAG, dChip and GEMCA, were applied to the data set, and only those regions recognized at least by two algorithms were identified as CNVs. Most CNVRs identified in the Korean population were rare (<1%), occurring just once among the 116 individuals. When CNVs from the Korean population were compared with CNVs from the three HapMap ethnic groups, African, European, and Asian; our Korean population showed the highest degree of overlap with the Asian population, as expected. However, the overlap was less than 40%, implying that more CNVs remain to be discovered from the Asian population as well as from other populations. Genes in the novel CNVRs from the Korean population were enriched for genes involved in regulation and development processes.
  
  
  CONCLUSIONS
  CNVs are recently-recognized structural variations among individuals, and more CNVs need to be identified from diverse populations. Until now, CNVs from Asian populations have been studied less than those from European or American populations. In this regard, our study of CNVs from the Korean population will contribute to the full cataloguing of structural variation among diverse human populations.
authors.affiliation: Medical Genomics Research Center, KRIBB, 52 Eoeun-dong, Yuseong-gu, Daejeon 305-806, Republic of Korea. twkang76@kribb.re.kr
authors.forename: Tae-Wook
authors.initials: TW
authors.lastname: Kang
authors.forename: Yeo-Jin
authors.initials: YJ
authors.lastname: Jeon
authors.forename: Eunsu
authors.initials: E
authors.lastname: Jang
authors.forename: Hee-Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Jeong-Hwan
authors.initials: JH
authors.lastname: Kim
authors.forename: Jong-Lyul
authors.initials: JL
authors.lastname: Park
authors.forename: Siwoo
authors.initials: S
authors.lastname: Lee
authors.forename: Yong Sung
authors.initials: YS
authors.lastname: Kim
authors.forename: Jong Yeol
authors.initials: JY
authors.lastname: Kim
authors.forename: Seon-Young
authors.initials: SY
authors.lastname: Kim
mesh_terms: D044466:Asian People / Q000208:ethnology / Q000235:genetics; D018628:Gene Dosage; D014644:Genetic Variation; D005828:Genetics, Population; D015894:Genome, Human; D006801:Humans; D007723:Korea; D020411:Oligonucleotide Array Sequence Analysis